Very cool, thanks for the added info and good explanation. Your description probably can go right under the existing sticky...why recycle when you can reuse, and why replace when you can repair!

Probably worthwhile to put the ohmmeter on yours before you start tearing it apart, though. If you get the wild variation, then give mpr's trick a try!

Take care and enjoy the ride,
Greg

 

Thanks too mpr2007!

 

Topped it off this morning and it the gauge went straight to 1/1. Very satisfying to fix something and save $.

 

Glad to hear it worked out well. I have a question or 2.
To get to the fuel sender is it inside the fender on the passenger side just where the gas cap is? How long did it take you to take off the inside of the fender and do the job completely? Any surprises? I plan on doing my car this weekend.
Thank-You.

 

The sender is in the trunk.

Make sure that there is less than 1/2 tank of gas or you will have a mess when you pull the sender.

Remove the trunk trim panel behind the rear seat, pull sender plug, use large channel lock pliers to turn ring and it comes right out.

10 minute job to get it out.

Look in the DIY section as I believe the instructions are there or do a search.

 

Put the meter back on it and it read a very smooth ~0 ohms (empty) to about 133k (full). No jumping around. This can be done with a digital meter but is much easier to see with an old-school analog meter.

M

I checked mine after cleaning it and I get totally different measurements than you did. It may be my lack of ohms knowledge, but I show .20 at empty(arm hanging down) to .00 at full (arm held up) with a digital meter which is all I have.

I don't see any change in my gas gauge. Is it time to just get a new unit?

 

Assuming your VOM is working and that mpr2007's sender unit reflects the correct resistance, then I would conclude that yours is bad, the ~0 reading is at the wrong end of the measurement and the range sounds wrong as well.

At least Autohaus has the replacement so you're not stuck with stealer pricing:
Fuel Sender Unit)

Take care and enjoy the ride,
Greg

Addendum: Maybe they do. For some reason it shows that unit for the 320, but no listing for the 430. You might call and ask them. Might as well order the O ring at the same time.

 

Well, despite my Ohm readings whether backwards or not, I filled the tank and it does indeed show 1/1 Full.

Worked like a charm. Many thanks.

 

Apologies - I may have that backwards. I mentioned "~0 ohms (empty) to about 133k (full)" and it may be the other way around. I'll check and get back to the forum.

 

So I may not be crazy after all?

Mine went from 200 empty to 0 full on a digital.

 

I'm having a similar issue with the fuel gauge but slightly different symptoms. My tank reads "full" all the time. Took off the sender unit and tested it with an ohm meter and no issues there. Analog needle moved smoothly as I moved the arm up and down. Cleaned it a little and put it back in, but I still got the same "full" reading. So I went out and spent the money to get a new sender unit, but to my dismay that didn't solve the problem. I don't know what my next step is from here... any advice?

Thanks!

 

Does the needle drop down to E when car is switched off?

 

Yeah, it does drop when the car is off. Also, when I disconnect the sender unit the needle also drops.

 

Well, that rules out a stuck needle.

 

Haha, thanks Kobus. I may be a newbie, but I'm not that new...

 

Well, never does any harm to check. If my wife's car doesn't want to run, she will decide that it's either the battery that's flat or the car is out of gas, but that it's impossible to diagnose which one it is. ::surrender:

Hope my wife don't discover this forum.

 

Haha, yeah it's always good to keep those comments from the ladies. But I know what ya mean...
Any other ideas though? Could the actual gauge be malfunctioning? Or what about the line from the tank to the relay? I just replaced my K40 combination relay because it went bad when my fuel pump went out. I'm pretty sure that the sending unit runs through that relay. And all my fuses are good too. So I'm at a loss right now...

 

Someone else posted the same problem on this forum some time ago, but he never got back with the solution.
The fact that it does change position with the sender unit unplugged, show that it is still communicating with the gauge. As I understand the other posts here, a high resistance causes the gauge to show full? Maybe damaged wiring or a bad connection? K40 itself? Try and unplug the K40 and see if that have an effect.

If you do find the problem, please post it here to help the next guy.

 

Hi I have w210 Mercedes E320 CDI year 2000, I’m having some trouble with my fuel gauge and was just wondering whether you could help me.

The problem occurred when I took out the instrument cluster in order to change a bulb, after this it never worked properly. If I filled the car up to the brim (and therefore should show full) it reads between full and the ¾ mark, when the fuel is also being consumed it will also come down so therefore is always inaccurate by this degree (1/2 of a ¼). I know that it's not the sender unit and other stuff which is being said because when I smack the cluster/dash it moves up a bit, I have opened the cluster up again and have noticed that this gauge is much “sticky” and more resilient to move than all other dials such as temp? Is this normal?

I think the problem maybe an electrical fault or a lose connection somewhere but I am not sure

Has anyone else encountered this problem?

How can I fix the problem?

Cheers

 

I found this thread because I think I'm having problems with my fuel sending unit, but no one has described the symptoms I'm experiencing.

If my unit is defective, would it prevent the car from starting? Basically, for some reason fuel isn't getting to the engine when I try to start (no matter how full the tank is), however if I splash some gas into the tank or shake the car from the trunk, the engine will start. This began first when the tank was low, then proceeded to keep happening the more fuel I put in, culminating with the car not starting with a 3/4 full tank of gas. I've already ordered a new unit just in case mine's not fixable, but are there any other components that could cause this?

Thanks and appreciate all the help!

 

It sounds like your splash bowl is not properly filling from the tank. I'm not sure about your car, but on mine the splash bowl is filled using a venturi pump, powered by the return fuel flow. The FSM shows such a system used for engines 104, 112, 113, 119 and 606.

If your return fuel flow has been physically altered, or if it is insufficient, the splash bowl will not fill. A partially-plugged filter or failing pump could cause insufficient return flow.

 

Wagon help for this issue?

I'm reading a lot of interesting information on a problem I've been having, which I'm hoping I can soon put to good use as my fuel gauge now reads completely empty all the time.

My question, however, is this: how do I get to the fuel tank sender unit in a W210 wagon? as there's no trunk, hence no trunk liner, and the part is different than the sedan part (unfortunately, as the sedan part is on eBay for less than half the price of the wagon one elsewhere).

Anyone have any idea how to get to the sender in a wagon? is it near the CD changer in the cargo area? Or is it behind the rear seat, near the battery?

thanks!

 

I'm reading a lot of interesting information on a problem I've been having, which I'm hoping I can soon put to good use as my fuel gauge now reads completely empty all the time.

My question, however, is this: how do I get to the fuel tank sender unit in a W210 wagon? as there's no trunk, hence no trunk liner, and the part is different than the sedan part (unfortunately, as the sedan part is on eBay for less than half the price of the wagon one elsewhere).

Anyone have any idea how to get to the sender in a wagon? is it near the CD changer in the cargo area? Or is it behind the rear seat, near the battery?

thanks!

Bumping this as I have the same issue, fuel gauge reads empty even with a full tank. I also have a wagon, looking for some info on how to access the fuel sender, and how to diagnose if my issue is with the sender or the gauge itself, thanks in advance for any responses!